The European Medicines Agency has said the risk of serious psychiatrics problems and even suicide are too high. And since at-risk patients cannot be identified, marketing of the drug should be suspended.
The agency approved Acomplia in 2006, but by early 2007 there were concerns about an elevated mental health risk.
In June 2007, a Food and Drug Administration advisory panel unanimously recommended the FDA not approve the drug. A month later, Acomplia's maker, Sanofi, withdrew its application for approval. In clinical trials, volunteers taking Acomplia were 50 per cent more likely to have adverse reactions than those taking a placebo.
Sanofi was in the process of re-targeting the drug, by testing it as a treatment for conditions made worse by excess weight, such as diabetes, hardening of the arteries, or lipid disorders.
The company planned to reapply to the FDA in the fourth quarter of 2009, seeking approval as a diabetes treatment.
Acomplia was the first in a class of drugs called selective cannabinoid receptor CB1 antagonists. It blocked hunger signals in the brain, cutting a person's drive to eat. Earlier this month, Merck stopped development on taranabant, another drug in the same class as Acomplia, because it made users depressed and irritable.
The suspension of Acomplia sales was a severe blow to the most promising anti-obesity drug since fen-phen, the drug combination recalled more than a decade ago after concerns arose it raised the risk of heart attacks, strokes, and diabetes. However, it may also scuttle development of other new medications to fight obesity.
Pharmaceutical companies fear regulators may be hypercritical in the future, and less likely to approve new drugs. Smaller biotech companies may find it harder to get investor funding or find alliances with major companies.
NeuroSearch A/S has been seeking a major pharmaceutical partner to develop its experiemental drug tesofensine. It targets the brain to suppress overeating, but in a different way than Acomplia. It maintains higher than normal levels of 3 brain chemicals, prolonging the pleasure from food, and making users feel full earlier.
AstraZeneca is developing 2 drugs in the same class as Acomplia, however, they will be sold as treatments for Type 2 diabetes, not diet drugs.
